Characterizing HR 3549 B using SPHERE Article - Septembre 2016

D. Mesa, A. Vigan, V. d'Orazi, C. Ginski, S. Desidera, M. Bonnefoy, R. Gratton, M Langlois, F. Marzari, S. Messina, J. Antichi, B. Biller, M. Bonavita, E. Cascone, G. Chauvin, R. U. Claudi, I. Curtis, D. Fantinel, M. Feldt, A. Garufi, R. Galicher, Th. Henning, S. Incorvaia, A.-M. Lagrange, M. Millward, C. Perrot, B. Salasnich, S. Scuderi, E. Sissa, Z. Wahhaj, A. Zurlo, V. D’orazi

D. Mesa, A. Vigan, V. d'Orazi, C. Ginski, S. Desidera, M. Bonnefoy, R. Gratton, M Langlois, F. Marzari, S. Messina, J. Antichi, B. Biller, M. Bonavita, E. Cascone, G. Chauvin, R. U. Claudi, I. Curtis, D. Fantinel, M. Feldt, A. Garufi, R. Galicher, Th. Henning, S. Incorvaia, A.-M. Lagrange, M. Millward, C. Perrot, B. Salasnich, S. Scuderi, E. Sissa, Z. Wahhaj, A. Zurlo, V. D’orazi, « Characterizing HR 3549 B using SPHERE  », Astronomy and Astrophysics - A&A, septembre 2016, A119. ISSN 0004-6361

Abstract

Aims. In this work, we characterize the low mass companion of the A0 field star HR3549. Methods. We observed HR3549AB in imaging mode with the the NIR branch (IFS and IRDIS) of SPHERE@VLT, with IFS in YJ mode and IRDIS in the H band. We also acquired a medium resolution spectrum with the IRDIS long slit spectroscopy mode. The data were reduced using the dedicated SPHERE GTO pipeline, purposely designed for this instrument. We employed algorithms such as PCA and TLOCI to reduce the speckle noise. Results. The companion was clearly visible both with IRDIS and IFS.We obtained photometry in four different bands as well as the astrometric position for the companion. Based on our astrometry, we confirm that it is a bound object and put constraints on its orbit. Although several uncertainties are still present, we estimate an age of 100-150 Myr for this system, yielding a most probable mass for the companion of 40-50MJup and T_eff 300-2400 K. Comparing with template spectra points to a spectral type between M9 and L0 for the companion, commensurate with its position on the color-magnitude diagram.

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